package com.young.security;

import java.io.UnsupportedEncodingException;
import java.net.URLDecoder;
import java.net.URLEncoder;
import org.apache.commons.codec.DecoderException;
import org.apache.commons.codec.binary.Base64;
import org.apache.commons.codec.binary.Hex;
import org.apache.commons.lang3.StringEscapeUtils;


/**
 * 封装各种格式的编码解码工具类.
 * <p>
 * 1.Commons-Codec的 hex/base64 编码
 * 2.自制的base62 编码
 * 3.Commons-Lang的xml/html escape
 * 4.JDK提供的URLEncoder
 *
 * @author calvin
 */
public class Encodes {
  
  private static final String DEFAULT_URL_ENCODING = "UTF-8";
  private static final char[] BASE62 = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz".toCharArray();
  
  /**
   * Hex编码.
   */
  public static String encodeHex(byte[] input) {
    return Hex.encodeHexString(input);
  }
  
  /**
   * Hex解码.
   */
  public static byte[] decodeHex(String input) {
    try {
      return Hex.decodeHex(input.toCharArray());
    } catch (DecoderException e) {
      throw Exceptions.unchecked(e);
    }
  }
  
  /**
   * Base64编码.
   */
  public static String encodeBase64(byte[] input) {
    return Base64.encodeBase64String(input);
  }
  
  /**
   * Base64编码, URL安全(将Base64中的URL非法字符'+'和'/'转为'-'和'_', 见RFC3548).
   */
  public static String encodeUrlSafeBase64(byte[] input) {
    return Base64.encodeBase64URLSafeString(input);
  }
  
  /**
   * Base64解码.
   */
  public static byte[] decodeBase64(String input) {
    return Base64.decodeBase64(input);
  }
  
  /**
   * Base62编码。
   */
  public static String encodeBase62(byte[] input) {
    char[] chars = new char[input.length];
    for (int i = 0; i < input.length; i++) {
      chars[i] = BASE62[((input[i] & 0xFF) % BASE62.length)];
    }
    return new String(chars);
  }
  
  /**
   * Html 转码.
   */
  public static String escapeHtml(String html) {
    return StringEscapeUtils.escapeHtml4(html);
  }
  
  /**
   * Html 解码.
   */
  public static String unescapeHtml(String htmlEscaped) {
    return StringEscapeUtils.unescapeHtml4(htmlEscaped);
  }
  
  /**
   * Xml 转码.
   */
  public static String escapeXml(String xml) {
    return StringEscapeUtils.escapeXml(xml);
  }
  
  /**
   * Xml 解码.
   */
  public static String unescapeXml(String xmlEscaped) {
    return StringEscapeUtils.unescapeXml(xmlEscaped);
  }
  
  /**
   * URL 编码, Encode默认为UTF-8.
   */
  public static String urlEncode(String part) {
    try {
      return URLEncoder.encode(part, DEFAULT_URL_ENCODING);
    } catch (UnsupportedEncodingException e) {
      throw Exceptions.unchecked(e);
    }
  }
  
  /**
   * URL 解码, Encode默认为UTF-8.
   */
  public static String urlDecode(String part) {
    
    try {
      return URLDecoder.decode(part, DEFAULT_URL_ENCODING);
    } catch (UnsupportedEncodingException e) {
      throw Exceptions.unchecked(e);
    }
  }
}
